The mixing of fluids is frequently desired in order to perform chemical reactions. Representatively, a controlled and homogeneous mixing of reagents is generally desirable. In certain applications or operating environments, the combined volume required for the mixture may need to be kept as small as possible so that the consumption of reagents does not become excessive.
A common conventional means of mixing two or more miscible liquids is to stir, either mechanically with a utensil or by exploiting certain fluidic forces, to produce localized regions corresponding to relatively high fluid flow rates that generally operate to produce localized turbulent forces within the fluid field. This turbulence generally provides a relatively large contact surface between the liquids such that diffusion of the fluid components into each other produces a substantially homogeneous mixture. When the flow velocity of a fluid is relatively small, the corresponding Reynolds number R may take on values less than unity as in       R    =                  Ud        v            <      1        ,where U is the mean flow velocity, d the diameter of the flow channel, and v the kinematic viscosity. Low Reynolds number environments may be encountered, for example, in capillary systems, systems where the device scales are relatively small and/or fluid flow velocities are relatively small, or systems where viscous forces largely dominate the inertial forces produced. In such cases as these, the inertial forces that produce turbulence and the resulting relatively large contact areas generally required to promote mixing typically cannot be achieved. Accordingly, fluid mixing in these types of systems is generally regarded as a diffusion limited process usually requiring the fluid components to remain in relative contact with each other for prolonged periods of time in order to achieve any substantial mixing. For many applications where two or more fluid components are to be mixed and/or dispensed rapidly in the regimen of low Reynolds numbers, this may be unacceptable. Moreover, while pre-mixing of fluid components in certain liquid phase applications may offer an alternative option, pre-mixing of gas phase reaction components is generally not possible. Accordingly, what may be desired is a system and method for the rapid production of substantially homogeneous fluid mixtures in low Reynolds number regimes.